Patent GB-632641-A (GB)
Title: Improvements in and relating to photographic sensitisers and process for sensitising silver halide emulsions
IPC: C09B23/00
Filed: 1946-02-18
Abstract: Di - (2 - methylbenzthiazolyl - 6 -) - methane is prepared by oxidizing p : p1 - dithioacetyl - di-aminodiphenylmethane with potassium ferricyanide.  1 : 3 - Di - p - nitrophenoxypropane is prepared by heating together sodium p-nitrophenolate and trimethylene dibromide.  1 : 3 - Di - p - aminophenoxypropane is prepared by reducing 1 : 3-di-p-nitrophenoxypropane with tin and HCl.  1 : 3 - Di - p - acetaminophenoxypropane is prepared by acetylating 1 : 3 - di - p - aminophenoxypropane with acetic acid and acetic anhydride.  1 : 3 - Di - p - thioacetaminophenoxypropane is prepared by heating 1 : 3 - di - p - acetaminophenoxypropane with P2S5 in pyridine.  1 : 3 - Di - (2 - methylbenzthiazoloxy - 5) - propane is prepared by oxidizing 1 : 3-di-p-thioacetaminophenoxypropane in aqueous-alcoholic NaOH solution with potassium ferricyanide.ALSO:Bis-cyanines and bis-styryl dyes are derived from double quaternary cyclammonium salts of the formula <FORM:0632641/IV (c)/1> wherein Y and Y1 are the same or different hetero atoms of the oxygen group, R is a quadrivalent radical derived from a benzene ring which may be substituted and wherein both the N-atoms of the azole rings are in p-positions, or from diphenyl, the m- and p-carbon atoms being shared by an azole ring, or from two phenyl rings, which may be substituted and are linked by a bivalent group or chain such as methylene, polymethylene, xylylene, diethylene ether, or diethylene thioether and in which the m- and p-carbon atoms of each phenyl ring are shared by an azole group, Q is an alkyl, alkenyl, aryl, aralkyl, or like group substituted or not, and X is an anion, by reaction with known intermediates.  The dyes obtained may be pseudocyanines, carbocyanines, polycarbocyanines, merocyanines, or styryl dyes, and may be symmetrical or unsymmetrical.  The methine chains may be substituted.  In examples, dyes are prepared from (1) 2-(b -acetanilidovinyl)-benzthiazole ethiodide and 2 : 21-dimethylbenzo - p - bis - (thiazole dimethylsulphate) by refluxing with acetic anhydride and sodium acetate ; (2) 2 - (b  - ethyl) - (b - methylmercaptovinyl) - a  - naphthathiazole dimethyl sulphate and 2 : 21 - dimethyl - benzo - p - bis-(thiazole dimethyl sulphate) by refluxing with ethanol and triethylamine; (3) 2-(b -methyl)-(b  - methylmercaptovinyl) - benzthiazole ethyl methyl sulphate and di-(2-methylbenzthiazolyl)-5) - methane - di - (diethyl sulphate) by refluxing with ethanol and triethylamine, and (4) 2-ethylmercaptoquinoline ethiodide and 2 : 21 - dimethyl - benzo - p - bis - (thiazole diethyl sulphate) by refluxing with ethanol and triethylamine.  Samples have been furnished under Sect. 2 (5) of the bis-carbocyanine derived from di-(2-methylbenzoxazolyl - 6) - methane - di - (di-methylsulphate) and 2 - b  - anilinovinylbenzoxazole benzyl bromide, of 2 : 21-bis-(p-dimethylaminostyryl - bis - benzoxazole - 6-di-(benzyl bromide), of the bis-merocyanine dye from di - (2 - methylbenzthiazolyl - 5)-trimethylene glycol di - (dimethylsulphate) and 5 - acetanilidomethylene) - phenylrhodanine and of the cyclic bis-carbocyanine dye derived from bis-(2-methylbenzoxazole-6)-di-(dimethyl sulphate) and ethyl orthoformate.